Disc brakes typically employ one or more springs to urge the disc brake pads away from each other when braking pressure is released to avoid drag on the rotor. Many different shapes have been used for these springs, and a typical spring is a V-shaped wire that attaches to the top of the pad plate. This spring is nested between the caliper body bridge and the rotor. The V-spring attachment requires a small hole to be drilled into the edge of the pad plate, which is a costly operation. The wire form V-spring itself is expensive because it requires the wire to be bent at different angles and in different shapes.
In many applications the pad abutments are below the V-spring attachment to the pad. In these cases, the function force between the pad abutment and pad clips prevent the pad from moving away from the rotor in parallel fashion. Typically the top of the pad moves away while the bottom of the pad remains in contact with the rotor.
In many instances, the V-spring is trapped between the pad and the underside of the caliper bridge. The spring legs must be sufficiently long to remain engaged with the pad in all cases of pad to bridge gap tolerance. In many cases the V-spring will rub against the underside of the caliper bridge with a force large enough to cause the spring wire to wear or to cause the caliper body slide force to increase.